Revert of Draggable peeking/fullscreen launcher with transparent background.

ash/shelf/shelf_layout_manager.cc

Index: ash/shelf/shelf_layout_manager.cc
diff --git a/ash/shelf/shelf_layout_manager.cc b/ash/shelf/shelf_layout_manager.cc
index d5474587e1094ffe79c4f8b8d689435be23ec07a..3b2c1704ef60e16da604241b400ed1b09ec1865e 100644
--- a/ash/shelf/shelf_layout_manager.cc
+++ b/ash/shelf/shelf_layout_manager.cc
@@ -28,7 +28,6 @@
 #include "base/auto_reset.h"
 #include "base/command_line.h"
 #include "base/i18n/rtl.h"
-#include "ui/app_list/app_list_features.h"
 #include "ui/base/ui_base_switches.h"
 #include "ui/compositor/layer.h"
 #include "ui/compositor/layer_animation_observer.h"
@@ -426,16 +425,6 @@
       &keyboard_observer_);
 }
 
-void ShelfLayoutManager::OnAppListVisibilityChanged(bool shown,
-                                                    aura::Window* root_window) {
-  if (shelf_ != Shelf::ForWindow(root_window))
-    return;
-
-  is_app_list_visible_ = shown;
-  if (app_list::features::IsFullscreenAppListEnabled())
-    MaybeUpdateShelfBackground(AnimationChangeType::IMMEDIATE);
-}
-
 void ShelfLayoutManager::OnWindowActivated(ActivationReason reason,
                                            aura::Window* gained_active,
                                            aura::Window* lost_active) {
@@ -478,10 +467,6 @@
   // Handle all non active screen states, including OOBE and pre-login.
   if (state_.session_state != session_manager::SessionState::ACTIVE)
     return SHELF_BACKGROUND_OVERLAP;
-
-  // If the app list is active, hide the shelf background to prevent overlap.
-  if (is_app_list_visible_ && app_list::features::IsFullscreenAppListEnabled())
-    return SHELF_BACKGROUND_DEFAULT;
 
   if (state_.visibility_state != SHELF_AUTO_HIDE &&
       state_.window_state == wm::WORKSPACE_WINDOW_STATE_MAXIMIZED) {